如何使用C＃&删除SQL表记录SQL WHERE子句 [英] How to delete a SQL table record using C# & SQL WHERE clause

问题描述

大家好，



我想用C＃删除sql表记录。我已经尝试了下面提到的代码片段，但它没有用。然而，该消息显示数据记录被删除！应该是它应该是。我在声明中也找不到问题。



我尝试了什么：

Hi All,

I want to delete a sql table record using C#. I already tried the below mentioned code snippet but it didn't work. However the message is showing 'Data Record Deleted!' as it should it be. I can't find an issue in the statement also.

What I have tried:

private void btnDeleteData_Click(object sender, EventArgs e)
       {
           try
           {

               SqlComm = new SqlCommand("DELETE FROM MyDataTable WHERE DataID='@DataID'", SqlConn);
               SqlComm.Parameters.AddWithValue("@DataID", txtDataID.Text);
               SqlComm.ExecuteNonQuery();
               MessageBox.Show("Data record deleted!", "DB Connection With App.Config", MessageBoxButtons.OK, MessageBoxIcon.Asterisk);

               Clear();
               DisableButtons();
           }
           catch (Exception ex)
           {
               MessageBox.Show(ex.Message);
           }
       }

有人可以试着解决这个问题吗？



谢谢和问候，

Chiranthaka

Could someone please try to solve this matter?

Thanks and regards,
Chiranthaka

推荐答案

代码看起来不错，所以最多可能的事情是WHERE子句不匹配任何行。

首先检查命令影响的行数：ExecuteNonQuery返回：

The code looks OK, so the most likely thing is that the WHERE clause matches no rows.
Start by checking how many rows the command is affecting: the ExecuteNonQuery returns that:

SqlComm.Parameters.AddWithValue("@DataID", txtDataID.Text);
int deleted = SqlComm.ExecuteNonQuery();
MessageBox.Show(string.Format("{0} rows deleted.", deleted), "DB Connection With App.Config", MessageBoxButtons.OK, MessageBoxIcon.Asterisk);

如果该值指示为零，则使用调试器确切检查txtDataId中的内容，并使用SSMS手动检查数据库是否存在完全匹配。

If that indicates zero, then use the debugger to check exactly what is in txtDataId and manually check the DB for exact matches using SSMS.

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